# Build stage
FROM golang:1.25.3-alpine AS builder

# Install build dependencies
RUN apk add --no-cache git ca-certificates tzdata

# Set working directory
WORKDIR /app

# Copy go mod files
COPY go.mod go.sum ./

# Download dependencies
RUN go mod download

# Copy source code
COPY . .

# Build the application
# CGO_ENABLED=0 for static binary, GOOS=linux for Linux compatibility
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -ldflags="-w -s" -o server ./cmd/server/main.go

# Runtime stage
FROM alpine:latest

# Install CA certificates for HTTPS requests (OAuth)
RUN apk --no-cache add ca-certificates tzdata

# Create non-root user
RUN addgroup -g 1000 appuser && \
    adduser -D -u 1000 -G appuser appuser

WORKDIR /app

# Copy binary from builder
COPY --from=builder /app/server .

# Change ownership to non-root user
RUN chown -R appuser:appuser /app

# Switch to non-root user
USER appuser

# Expose port (Fly.io uses PORT env variable)
EXPOSE 8080

# Health check
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
    CMD wget --no-verbose --tries=1 --spider http://localhost:8080/health || exit 1

# Run the application
CMD ["./server"]